Neuroscience research has identified chemicals, proteins, and hormones that can lead to a range of behavior — from peaceful to aggressive states of mind — and current neuroscience methodologies even identify a substance that works as a messenger in the brain responsible for financial decisions. Still missing, however, are guiding rules that govern how individual actors in the brain perform in response to the natural and social environment. Researchers from Hokkaido University and the University of Tsukuba will discuss recent discoveries related to internal and social behavior and mathematical tools that provide insight into what is happening in the brain.